Thermostatic controlling device for furnaces



April'7; 1942. J, H, HEMRY THERMOSTATIC CONTROLLING DEVICE FOR FURNACES Filed Nov. '7, 1959 attorneys Patented Apr. 7, 1942 UNITED 'STATEE ort'lc a THERMQSTATIC CONTROLLING DEVICE FOR FURNACES JaniesH. Hemry, Springfield, Ohio Application November 7, 1939, Serial No. 303,268

3 Claims. (01.236-16) This invention relates to a thermostatic control'more particularly adapted for a coal burning furnace which employs a draft damper and a check damper.

The object of this invention is to provide a thermostatic control mechanism which will be simple in construction and effective in operation and easily installed in connection with any furnace now in use of the type referred to.

A further object of the invention is to provide thermostatic controlling mechanism which may be readily adjusted to different weather conditions.

In the accompanying drawing:

Fig. 1 is a side elevation of a furnace showing the improved thermostatic mechanism applied thereto.

Fig. 2 is a front elevation .of a portion of the furnace and thermostaticcontrolling mechanism on an enlarged'scale.

Fig. 3 is an enlarged section on the line 3-3 of Fig. 1.

Fig. 4 is a rear elevation of a portion of the device.

.Referri-ng to the drawing, I represents a coal burning furnace of a well known type, .2 :a portion of the smoke pipe leading therefrom, 3 the check damper and 4 the draft damper, this draft damper being hinged to the door 5 of the ash pit of the furnace in the usual way. The check damper 3 is connected to one end of a pivoted channel-shaped bar 6 by a chain 1 having a hook 8, the hooked portion of which is passed through a hole of a clip H] which is bolted to the bar 6.

The clip It, as shown in Fig. 4, is provided with a series of openings ID in any one of which openings the hook 8 may be placed so that the extent of the opening of the check damper 3 may be varied as desired. In some furnaces the position of the smoke pipe and its check damper is different from that shown in the drawing; that is, the smoke pipe extends at right angles to the position of the smoke pipe shown in the drawing. In the event of such an installation, I provide on the other end of the bar 6 a clip It also provided with a series of holes H5 as shown in Fig. 2 to which the chain of the check damper may be attached in the same manner as described in connection with the clip It, this clip it being secured to the bar by a bolt H.

The draft damper 4 is connected to the other end of the bar 6 by a chain 1 l which has a hook it, the hook portion of which is passed through any one of a series of openings l3 in a clip M,

which clip is secured to the bar 5 by the bolt l1 with the clip l6 extending upwardly and the clip l4 downwardly. The bar 6 extends across the top of the furnace and is pivoted midway its length as at H! to one arm I9 01' an inverted U-shaped bracket l9, the other arm I9" of this bracket being for-med with an elongated slot l9a through which the bar passes so as to be guided thereby, this arm 19" being longer than the arm Ill; The bracket l9 has secured thereto a vertical stem 20 which is secured by a set screw 2! to "a flanged sleeve 22, the flange .23 of the sleeve being in turn secured to a plank 24' which is fastened to the joist of the fioor of the structure in which the furnace is installed, one of these joists being indicated at 24.

interposed between the horizontal portion of the bracket l9 and a screw 25 in the bar 6 is a thermostat 26 which in the present case is shown as of the well known expanding. fiuid bellows type. The upper portion of the thermostat .is rigidly attached to the bracket l9 in any suitable way, such as by the screw 26, and the lower portion adapted to bear against the screw 2', .the screw being locked by the lock nut 2.5.

An adjustable weight 2.1 is slidably mounted between the pivot point l8 and the clip LB, this weight being held in different positions of adjustment by the set screw 28, this weight acting torock the bar in the direction opposite to the influence of the thermostat and hold the screw 25 against the thermostat, the lower portion of the thermostat being provided with a small end which fits in the conical recess in the block 26, the bar and thermostat are maintained in fixed relation with each other; that is, the bar will not be permitted to move either laterally or endwise with respect to the thermostat.

The weight 21 is made adjustable so as to compensate for the difference in weight between the two dampers and their connections, the draft damper 4 and chain ll generally being heavier than the check damper 3 and its chain. The weight is so adjusted, therefore, that it will serve to overcome the difference in weight between the damper 3 and its chain 1 and that of the damper 4 and its chain II and thereby, serve to tilt the bar 6 when the thermostat contracts and maintain the screw 25 in contact with the thermostat. After a proper adjustment of the parts has been made the weight 21 is thereafter left undisturbed.

In operation, the parts are initially adjusted for a given temperature, the hook l2 having been placed in one of the openings of the clip l4, and the weight 21 having been adjusted to a proper position and then locked by the set screw 28. For instance, as shown in Fig. 1 the adjustment is such that both the draft damper and the check damper are partly open, the hook l2 having been placed in the proper aperture in the clip I4 to effect this adjustment and the hook 8 placed in the proper aperture in the clip In to determine the extent of opening of the check draft damper. As the temperature rises and the thermostat expands the bar 6 will be rocked to further open the check damper and permit the draft damper to move to closed position. As the temperature lowers and the thermostat contracts the bar 6 will rock so as to permit the check damper 3 to move toward closing position and cause the draft damper 4 to be moved to opening position.

By-this construction it Will be seen that the thermostat is placed directly above the furnace or in the space between the furnace head and the floor. In installing the thermostat at this point it i more accurately responsive to changes in temperature, as the temperature of the air above the furnace is more uniformly in proportion to the temperature of the interior of the furnace head.

Having thus described my invention, I claim:

1. In a thermostatic controlling device for a furnace having a draft damper and a check damper, a structure adapted to be assembled as a unit before installation consisting of a single bracket, a bar pivotally connected to said bracket intermediate its ends and of a length sufficient to extend entirely across the top of the furnace to permit the draft damper and check damper of the furnace to be connected therewith by independent connections leading directly from said bar to said dampers, a thermostat responsive to the temperature of the air immediately above the furnace supported by said bracket and operable to tilt said bar, and means for supporting said structure above and independently of the furnace, said structure when assembled being of such dimensions as to permit it to cocupy the space above the furnace.

2. In a thermostatic controlling device for a furnace having a draft damper and a check damper, a structure adapted to be assembled as a unit before installation consisting of a single bracket, a bar pivotally connected to said bracket intermediate its ends and of a length sufficientto extend entirely across the top of the furnace to permit the draft damper and check damper of the furnace to be connected therewith by independent connections leading directly from said bar to said dampers, a thermostat responsive to the temperature of the air immediately above the furnace supported by said bracket and operable to tiltsaid bar, and means for supporting said structure above and independently of the furnace, said means being adjustable as to height, said structure when assembled being of such dimensions as to permit it to 00- cupy the space above the furnace.

3. In a thermostatic controlling device for a furnace having a draft damper and a check damper, a structure adapted to be assembled as a unit before installation consisting of a single bracket, a bar pivotally connected to said bracket intermediate its ends and of a length sufiicient to extend entirely across the top of the furnace to permit the draft damper and check damper of the furnace to be connected therewith by independent connections leading directly from said bar to said dampers, a thermostat responsive to the temperature of the air immediately above the furnace supported by said bracket and operable to tilt said bar, a weight on said bar to assist in tilting the bar in the opposite direction, and means for supporting said structure above and independently of the furnace, said structure when assembled being of such dimensions as to permit it to occupy the space above the furnace.

JAMES H. HEMRY. 

